Updating shmem_get_policy to use the vma_policy if provided.
This is to allows us to safely provide shmem_vm_ops to the vma when the vm_file
has not been setup which is the case on the pseudo vmas.
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Nathan T Zimmer <nzimmer@xxxxxxx>
---
mm/shmem.c | 18 +++++++++++++++---
1 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index a15a466..9bd599b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -921,8 +921,11 @@ static struct page *shmem_swapin(swp_entry_t swap, gfp_t gfp,
/* Create a pseudo vma that just contains the policy */
pvma.vm_start = 0;
pvma.vm_pgoff = index;
- pvma.vm_ops = NULL;
pvma.vm_policy = spol;
+ if( pvma.vm_policy )
+ pvma.vm_ops = &shmem_vm_ops;
+ else
+ pvma.vm_ops = NULL;
return swapin_readahead(swap, gfp, &pvma, 0);
}
@@ -934,8 +937,11 @@ static struct page *shmem_alloc_page(gfp_t gfp,
/* Create a pseudo vma that just contains the policy */
pvma.vm_start = 0;
pvma.vm_pgoff = index;
- pvma.vm_ops = NULL;
pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, index);
+ if( pvma.vm_policy )
+ pvma.vm_ops = &shmem_vm_ops;
+ else
+ pvma.vm_ops = NULL;
/*
* alloc_page_vma() will drop the shared policy reference
@@ -1296,8 +1302,14 @@ static int shmem_set_policy(struct vm_area_struct *vma, struct mempolicy *mpol)
static struct mempolicy *shmem_get_policy(struct vm_area_struct *vma,
unsigned long addr)
{
- struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
pgoff_t index;
+ struct inode *inode;
+
+ // If the vma knows what policy it wants use that one.
+ if (vma->vm_policy)
+ return vma->vm_policy;
+
+ inode = vma->vm_file->f_path.dentry->d_inode;
index = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
return mpol_shared_policy_lookup(&SHMEM_I(inode)->policy, index);
--
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